Rod bending apparatus and method

ABSTRACT

A portable, handheld apparatus having the capability to bend structural members or rods having one end fixed. A movable force exerting means in the form of a spaced pair of force exerting rollers is carried on a frame. A stationary, but rotatable roller is mounted on the frame opposite the force exerting means. The apparatus is positioned relative to a fixed rod to be bent so that the rod is between the force exerting rollers and the stationary roller. The apparatus also includes power means for moving the force exerting rollers toward the stationary roller and against the rod to cause it to bend. As the bending of the rod occurs, in addition to the movement of the force exerting rollers towards the stationary roller, the apparatus can tilt relative to the rod and adjust its position longitudinally of the rod, to thereby maintain contact between the force exerting rollers and the rod during bending. Rotation of the rollers accommodates this movement of the apparatus relative to the rod. The tilting of the apparatus effects a change in the direction of the force exerted on the rod by the force exerting means as the bending is taking place, which change in direction maintains at least a major component of that force acting normal to the rod axis. In the illustrated apparatus, the force exerting rollers and the stationary roller define an open space between them for direct transverse insertion and removal of the rod. Analogous bending methods are provided.

United States Patent [191 Ware 1 Sept. 30, 1975 1 ROD BENDING APPARATUSAND METHOD Donald G. Ware, 1 1262 Sierra, Fontana, Calif. 92335 [221Filed: Jan. 4, 1974 [2]] Appl. No.: 430,631

[76] lnventor:

Primary Exunziner-Milton S. Mehr Allurncy, Agent, or Firm-Robert M.Ashen [57] ABSTRACT A portable, handheld apparatus having the capabilityto bend structural members or rods having one end fixed. A movable forceexerting means in the form of a spaced pair of force exerting rollers iscarried on a frame. A stationary, but rotatable roller is mounted on theframe opposite the force exerting means. The apparatus is positionedrelative to a fixed rod to be bent so that the rod is between the forceexerting rollers and the stationary roller. The apparatus also includespower means for moving the force exerting rollers toward the stationaryroller and against the rod to cause it to bend. As the bending of therod occurs, in addition to the movement of the force exerting rollerstowards the stationary roller, the apparatus can tilt relative to therod and adjust its position longitudinally of the rod, to therebymaintain contact between the force exerting rollers and the rod duringbending. Rotation of the rollers accommodates this movement of theapparatus relative to the rod. The tilting of the apparatus effects achange in the direction of the force exerted on the rod by the forceexerting means as the bending is taking place, which change in directionmaintains at least a major component of that force acting normal to therod axis. In the illustrated apparatus, the force exerting rollers andthe stationary roller define an open space between them for directtransverse insertion and removal of the rod. Analogous bending methodsare provided.

7 Claims, 3 Drawing Figures Sept. 30,1975 Sheet 1 of 2 U.S. Patent US.Patent Sept. 30,1975 Sheet 2 of2 3,908,425

RED BENDING APPARATUS AND METHOD BACKGROUND OF THE INVENTION l. Field ofthe Invention The invention relates to apparatus and methods for bendingrods and other elongated structural members, particularly ones havingone end fixed.

2. Description of thePrior Art In virtually all construction projects,structuralmembers comprising metal bars or rods having other thanrectilinear form are utilized. Such structural members are oftenpre-bent into the desired shape and then transported to the constructionsite. The transportation and handling is difficult and costly.

Some prior art devices have arisen for bending and forming structuralmembers on site. Such devices have, however, exhibited certaindeficiencies. For example, many such devices are bulky, unwieldy, and/orstationary, so that the members to be formed must be transported fromvarious points of the construction site at which they are stored to thebending apparatus and then transported to the points of the site atwhich they are to be used. Another drawback of existingdevices is that,generally speaking, they require that both ends of the member to beformed be free. Thus,-such devices have lacked the capability of forminga structural member after it has been fixed in place. This constitutes asubstantial deficiency since it is often difficult to determine exactlywhat angle, height or position of bend will be appropriate for aparticular member until it has been put in place. Generally, under theprior art capabilities, shaping and forming of structural members inplace have been effected by a relatively unsophisticated apparatus andmethods such as simple hammering of a fixed bar until the desired angleis achieved. Such procedures are inherently unsatisfactory because ofthe disproportionate amount of time and effort required,

and the imprecision of bend, as well as the danger to workers and to theintegrity of the structural member;

Therefore, there has been a recognized but unfulfilled need for aportable apparatus for bending and forming structural members such asrods, bars, and pipes, especially when such members have one end fixed.

bending structural members including solid or hollow metal bars or rods,particularly those have one end fixed. Rod bending apparatus includes aportable frame means upon which is mounted movable force exerting rollermeans for exerting bending force upon a structural rod or bar member; astationary roller means for reacting against the rod during exertion offorce thereupon is also mounted upon the frame means, spaced from andopposite the force-exerting roller means. Power means are operable tomove the force-exerting roller means against the rod. In operation, asbending of a rod fixed at one end proceeds, the apparatus adjusts itsposition to accommodiat'e the changing shape of the rod. In theillustrated embodiment,'tl1e frame means tilts and the rollermeansrotate so as to maintain the roller means in contact with the rod andthe bending force applied to the rod. Thus, the direction of thrust ofthe bending force changes in a manner maintaining a large proportion ofthe force exerted normal to the rod axis; this facilitatesfu'rtherbending The'apparatus further includes handle means by'which theframe means can be positioned relative to the rod and Apparatus andmethods are provided for forming and supported while the bending occurs.The force-exerting means may be hydraulically powered in a preferredembodiment.

In the drawings: I

FIG. 1 is a sideelevation of rod bending apparatus in accordance withthe invention, aligned with a rodtto be bent;

FIG.'2 comprisesa top plan view of the apparatus and rod of FIG. 1; and

FIG. 3 comprises-a side view of the rod bending apparatus and the rod ofFIG. -1, the rod being bent in accordance with the invention.

As shown in FIGS. 1 and 2, rod bending apparatus 10 includes a framemeans 12. The illustrated frame means 12 is a generally rectangular fiatmetal plate. It is preferably made of strong and rigid, but relativelylightweight, material such as aluminum. The plate 12 is shown disposedin a generally vertical plane, and the other portions of the apparatus,to be described, are conveniently mounted on one vertical face 13 of theplate. Theapparatus is illustrated in this orientation for bending avertical rod 52 that is fixed at its lower end 54. The apparatus isusable in any other desired orientation. A.hydraulic cylinder'14 issecured to the rearward portion of the face 13. The cylinder 14 which isgenerally cylindrical has its axis extending generally horizontal andfrom end to end of the plate 12. The cyl-. inder 14 has extensionportions 17 at its front and rear ends. Each extension portion 17 isreceived in a mounting bracket 16 that is solidlyfixed to the face 13 ofthe frame plate 12 as by means of screws 15.

Cylinder l4 defines aninterior volume or chamber 18 which receivespiston means20. Piston means 20 includes a head portion 22 whoseperiphery, slides within chamber 18 and. further includes a plungerportion 26. The plunger portion 26 comprises an. elongated sectionconnected to the head portion 24 and extend: ing substantiallyperpendicular thereto in alignment with the cylinder axis. The forwardend of the plunger portion 26 extends through an opening 27 in theforward end of the cylinder 14 and in the forward extension portion 17.i

A pair of apertures 28 defined by cylinder 14 communicate with oppositeends of chamber 18. A hose 30 is connected to each aperture 28. At theirouter ends, hoses 30 couple to a control box or means 36, which is inturn coupled by hose means 34 to a pump unit 32. Pump unit 32, shownschematically, pumps hydraulic fluid through hoses 30 and 34 to thehydraulic cylinder 14. The control means 36 is affixed to the top offrame plate 12 and includes a pair of control buttons 38 for controllingthe action of piston means 20.

At the forward end of plunger portion 26, a yoke 42 of force-exertingmeans 40 is attached. (As used herein, forward or advanced is defined astoward a rod to be bent or as to the right as depicted in thedrawings','conversely rearward" or retracted is defined as away from arod to be bent or as to the left" in the drawings.) Attachment of theyoke 42 to plunger portion 26 may be by conventional means, such as awelded connection, or the plunger portion and yoke may be integral. Theyoke 42 has a generally U-shaped configuration with the open end facingforward. The yoke 42 isdisposed parallel to and spaced from the plateface 13. At the forward end of each of the arms of the yoke 42 ismounted a contact means in the form of a roller 44. Each roller 44serves to transmit force from piston means 20 to a rod to be bent asdescribed below. Each of the rollers 44 is rotatably mounted upon atransversely extending pin 46 affixed in the bifurcated end of theassociated yoke arm.

In specific embodiments of the invention, the yoke may be of differentshape than the U configuration described herein, and the number andpositions and motion of the rollers may vary. These features should besuch as to permit the force exerting means to adapting to the changingshape of a rod being bent.

Forward of, and spaced from yoke means 42 is disposed reaction means inthe form of a stationary roller 48 rotatably mounted by means of athrust bearing 50 on a transverse shaft 51 affixed to face 13 of theframe plate 12. Roller 48 is stationary" in the sense that it is notmovable translationally with respect to the frame plate 12. A spacer 53is provided to position the roller 48 outwardly from face 13 andmaintain it approximately the same distance from face 13 as the rollers44. Thus, as shown in FIG. 2, the rollers 44 and 48 lie in a commonreference plane spaced from face 13. As will be described, the rod isdisposed and the bending action also occurs in this reference plane.

FIG. 1 shows a generally upright structural rod 52 having its lower end54 embedded and thereby fixed in a body of concrete 55. It is desired tobend the upper portion of the rod 52 about 90 into a generallyhorizontal position, the bending to take place generally about the pointalong the rod indicated as X. The apparatus may be handheld as by meansof a handle 56 mounted on the top of the frame plate 12, and positionedabout the rod 52 as shown in FIGS. 1 and 2. In this connection, therollers 44 and 48 define a vertical space between them, which is openand unobstructed from the side (FIG. 2). Preferably, as shown in thedrawings, the space between rollers 44 and 48 is larger than thedimension of the rod 52 so that the rod can be easily positioned fromthe side into that space. Alternatively, the spacing could be reduced sothat the rod has to be inserted longitudinally between the rollers 44and roller 48. As depicted in FIG. 2, rollers 44, 48 may have a concavecurvature so that as the movable rollers 44 advance, rod 52 is nestablewithin the side-to-side curvature of the rollers 44, 48 to retain therod in contact and prevent it from moving sideways out from between therollers.

The specific arrangement of these elements to produce a bend at adesired portion of a rod may vary with specific embodiments. In thedepicted embodimet, force exerting means 40 is aligned so that contactmeans 44 are substantially centered along the rod to either side of thedesired point X for initiation of bending.

Forward thrust for the yoke 42 is provided by passage of hydraulic fluidthrough the rearward hose 30, into the chamber 18 behind the piston headportion 22, producing hydraulic pressure forwardly against portion 22.The fluid simultaneously flows out of the chamber 18 in front of thehead portion through front hose 30. Passage of hydraulic fluid in such amanner is controlled by control unit 36, by the depression of theappropriate one of buttons 38.

In operation, upon forward motion of the yoke 42, rod 52 is firstengaged by rollers 44 and is then thrust into contact with roller 48.The rod then begins to bend around the stationary roller 48. As the yoke42 advances and rod 52 bends, rollers 44 and 48 rotate and permit motionof the apparatus along the surface of the bending rod. The contactrollers 44 roll longitudinally along the rod surface toward the freeupper end of the rod, and the reaction roller 48 rolls longitudinallyalong the rod surface in the opposite direction. The rear of the frameplate 12 also tilts upwardly. Thus, in addition to providing forwardmovement of the yoke 42, the apparatus permits the tilting of the frameplate 12, and the rotation of the rollers 44, 48 to accommodate movementof the apparatus longitudinally of and/or angularly with respect to thebending rod 52. Thus, the apparatus adapts its position and/ororientation to the changing shape of the rod. The direction of thethrust of the force exerting means and of the force transmitted to therod is thereby changed as the rod is bent. In this connection, as theframe plate 12 tilts and the rod is bent, a major component of the forceis exerted in a direction normal to the rod axis.

In a final position, as depicted in FIG. 3, rod 52 is bent to a rightangle. Of course, other angles of bend may be effected in accordancewith the invention. The depicted angle of tilt of frame means 12 isapproximately 45. It will be appreciated that particular angles of tiltdepend upon the specific dimensions of the rollers 44, 48, as well asthe distances between the centers thereof and the dimensions of the bar52.

Positive retraction of force exerting means 40 from the advanced,forward position depicted in FIG. 3, is effected by passage of hydraulicfluid through the forward hose 30 into the chamber 18 in front of headportion 22 and exit of fluid through rear hose 30 from the chamber 18behind head portion 22. This causes the piston means 20 to moverearwardly. This passage of fluid is controlled by control means 36through depression of the appropriate one of buttons 38. The apparatus10 then may be readily separated from the bent rod.

Alternatively, a return spring (not shown) of sufficient strength mightbe utilized for some applications in combination with a single actioncylinder, although the illustrated double-action cylinder is preferred.

Bending of rods with both ends free may also be effected by apparatus inaccordance with the invention.

It should be noted that apparatus 10 may be conveniently handheld byhandle 56 during operation. Pump unit 32 and hose means 34 areconfigured so that the pump unit may rest upon the ground duringoperation of apparatus 10. The pump unit may be wheel mounted formovement from place to place.

By way of example, in one particular working model, the frame plate isfabricated of aluminum for light weight and has a total length of about2 feet. The total weight of the model does not exceed about 22 pounds.Thus, an apparatus in accordance with the invention may be convenientlyhandheld during operation and may be transported conveniently to siteswhere its use is required. In this model, the hydraulic cylinderdevelops a thrust of about 9 tons and effectively bends a No. 7 ASTMStandard Reinforcing Bar having a nominal diameter of 0.875 inch. Theinitial space between the force-exerting and stationary rollers is aboutone inch, the force-exerting rollers advance about 3 inches, the rollersare all about 1 /2 inch thick, the front to rear length of the yoke isabout 3% inches, the distance between centers of the force-exertingrollers is about 5 inches, the radius of each force-exerting roller isabout k inch and the radius of stationary roller is about 1% inches.

The roller means are illustrated as solid, metal rollers. Such rollershave been found to be strong and durable while being relativelyeconomical to produce, and troublefree in operation. Other forms ofroller means to provide desired rotational movement may be utilized, asfor example, ball bearings or members mounted for limited pivotalmovement. Such roller means thus provide low-friction, rolling movementto accommodate the motion of the apparatus relative to the rod incidentto the bending of the rod.

In a modified form, the frame plate might be pivotally mounted on aself-standing support structure rather than being handheld. Suchstructure could be relatively lightweight and provided with wheels formovement from place to place.

Thus, apparatus in accordance with the invention provides the capabilityof precise and efficient on-site bending of structural members,particularly those in place. The easy portability of the apparatus inaccordance with the invention lends itself to ready and convenient use.

The description above does not define the invention, which is defined bythe appended claims.

I claim:

1. Apparatus for bending elongated members comprising:

a. a rigid, portable frame having means that define a mounting sidesurface;

b. a hydraulic cylinder means mounted on said side surface and with itsaxis generally parallel to said side surface;

0. force exerting roller means coupled to the cylinder means forreciprocating movement in the direction of said axis, said forceexerting means being movable between a rearward position and a forwardposition upon energization of said hydrailic cylinder means;

d. reaction roller means mounted on said side surface and spacedforwardly from the force exerting means when the latter is in itsrearward position a sufficient distance to permit an intermediateportion of an elongated structural member to be disposed in the spacetherebetween;

e. a separate hydraulic fluid pumping unit connected by flexible hosemeans to and in fluid communication with said cylinder means supportedby structure other than said frame; and

f. handle means on said frame for supporting said frame, cylinder means,force exerting roller means and reaction roller means for permittingmovement thereof relative to the portion of the axis of an elongatedmember prior to bending thereof, as said elongated member is bent byforce exerted thereon by said cylinder means and roller means;

g. said handle means and the member being bent providing the entiresupport for said frame, cylinder means, force exerting roller means andreaction roller means during bending of said member.

2. The apparatus of claim 1 wherein said reaction roller means and saidforce exerting means defining an unobstructed entrance to the spacetherebetween from opposite said side surface.

3. The apparatus of claim 2 wherein said reaction roller means and saidforce exerting means are spaced outwardly from said side surface.

4. The apparatus of claim 3 wherein said roller means comprise rollershaving concave roller surfaces for centering and maintaining thestructural member in place between the rollers in a reference bendingplane that extends generally normal to the axes of the rollers andspaced from said side surface.

5. The apparatus of claim 1 wherein said force exerting means comprisesa spaced apart pair of contact rollers.

6. The apparatus of claim 1 wherein said hydraulic cylinder meanscomprises a double-action cylinder for powered retraction as well asforce exertion.

7. The apparatus of claim 1 wherein said frame comprises a plate oflight-weight metal.

* l l l

1. Apparatus for bending elongated members comprising: a. a rigid,portable frame having means that define a mounting side surface; b. ahydraulic cylinder means mounted on said side surface and with its axisgenerally parallel to said side surface; c. force exerting roller meanscoupled to the cylinder means for reciprocating movement in thedirection of said axis, said force exerting means being movable betweena rearward position and a forward position upon energization of saidhydrailic cylinder means; d. reaction roller means mounted on said sidesurface and spaced forwardly from the force exerting means when thelatter is in its rearward position a sufficient distance to permit anintermediate portion of an elongated structural member to be disposed inthe space therebetween; e. a separate hydraulic fluid pumping unitconnected by flexible hose means to and in fluid communication with saidcylinder means supported by structure other than said frame; and f.handle means on said frame for supporting said frame, cylinder means,force exerting roller means and reaction roller means for permittingmovement thereof relative to the portion of the axis of an elongatedmember prior to bending thereof, as said elongated member is bent byforce exerted thereon by said cylinder means and roller means; g. saidhandle means and the member being bent providing the entire support forsaid frame, cylinder means, force exerting roller means and reactionroller means during bending of said member.
 2. The apparatus of claim 1wherein said reaction roller means and said force exerting meansdefining an unobstructed entrance to the space therebetween fromopposite said side surface.
 3. The apparatus of claim 2 wherein saidreaction roller means and said force exerting means are spaced outwardlyfrom said side surface.
 4. The apparatus of claim 3 wherein said rollermeans comprise rollers having concave roller surfaces for centering andmaintaining the structural member in place between the rollers in areference bending plane that extends generally normal to the axes of therollers and spaced from said side surface.
 5. The apparatus of claim 1wherein said force exerting means comprises a spaced apart pair ofcontact rollers.
 6. The apparatus of claim 1 wherein said hydrauliccylinder means comprises a double-action cylinder for powered retractionas well as force exertion.
 7. The apparatus of claim 1 wherein saidframe comprises a plate of light-weight metal.